K7S5a with AMD 1800xp model 8 Thouroughbred probs

Have I been sold the wrong processor, “1800xp model 8 Thoroughbred” running on an “ECS K7S5A ver 3.1 bios date 08/09/2002 s.

Three times since acquiring about 2 weeks ago, on start-up computer has reverted to original set-up of 1150 MHz, even date and time has reverted to 08/09/2002, giving messages “CMOS SETTING WRONG” & “CMOS MEMORY SIZE WRONG” requiring me to press F1 and run set-up.

computer shop that sold these to me is sure that the K7S5a will run with the “1800xp model 8 Thoroughbred” CPU.

AMD states ECS K7S5a is a recommended motherboards for “1800xp model 6”, ECS K7S5a is not on recommended list for “1800xp model 8”ECS site just states Athlonxp will run on ECS K7S5a

a bios update really isnt really needed since all you need to do is change the FBS settings to 133/133 and it should work! i have the same mobo with an 1700xp and when i first booted up the first time, my cpu was only recognised as 1100 mhz but after i changed the fbs, it went to the full 1700!

under normal circumstances fsb settings are 133/133, three times now it has reset itself to as new, 100/100 1150 MHz original date of 08/09/02 etc, won't boot and requires me to press F1 and reset bios, then ok for several bootups, no set pattern for this problem.